WAIKAWAU. THE DUNES.

Dune systems as good as this are a bit of a rarity. Just a few changes since the arrival of man. The moas are gone to be replaced with a few extras like rabbits, mammalian predators and an array of introduced plant species. Many dune systems elsewhere have fallen into the hands of coastal developers but this is, hopefully, less likely for the Waikawau dunes as they are part of the conservation estate.
The dunes have a remarkable ability to protect against coastal erosion, acting as a barrier against the intrusion of the sea. Much of this ability is dependant on the presence of two plant species, Spinifex and Pingaio.

Pingao

They obstruct the passage of sand carried by the onshore winds causing it to build up in the lee of the plants. The fore dunes grow in height as the native sand binders grow up through the deposited sand and trap yet more.
In circumstances of extreme and prolonged high winds the protective fore dunes  and the area behind can, in places, be blown out. For a while there is less protection against erosion, but dunes are self repairing ecosystems and will reform as long as there are native sand binders around to do the job.
In other areas, where residential developments have happened, the native sand binders have gone from the dunes. The dunes are less capable of adjusting to changes in the environment. Currently Environment Bay of Plenty is actively replanting native sand binders to restore this ability. With the prospect of future sea level rises from global warming this has to be a wise move.

There is one small upside to visiting areas where the wind has scoured right down to the water table. You could well be walking into prehistory. An old moa hunting site could be revealed, perhaps signs of fire on scattered rocks, or even collections of rounded moa gizzard stones. Who knows. It's always worth a look!